| Periodontal disease is destructive infectious diseases of periodontal tissue caused by various factors. Dental plaque biofilm bacteria and their products are initiating factor, but the destruction of bacteria is limited. A series of immune and inflammatory response caused by the bacteria are the main cause of periodontal tissue destruction. Therefore, its treatment is often affected by systemic, local and environmental factors and therapeutic effect is limited. There are no ideal methods in the current treatment. Although the antimicrobial drugs can effectively control the development of inflammation, there are many shortcomings such as: a low local drug concentration, large dosage and easy to induce resistance to drug when long-term use. Therefore, local medication, in particular, local application of controlled release agent is broadly concerned. Because it has sustained release of effective drug concentration, longer treatment time ,less frequency of administration,low toxicity and good patient compliance, local controlled release agents have become the main route of administration in periodontal disease treatment. But periodontal controlled release agents in current clinic have many deficiencies (such as short drug delivery time, incomplete release, etc.).Till now, there is no ideal controlled release agent can meet clinical requirements.Natural medicine research has been hot in recent years. Chinese gallnut has detoxification, hemostasis and other health effects. Its main active ingredient gallnut tannin have a broad spectrum of antimicrobial activity on the common periodontal pathogens and can inhibit endotoxin-induced inflammatory cytokine production, and can significantly reduce the activity of collagenase on the periodontal tissues has significant protective effect.On the basis of pre-existing sustained-release gel of gallnut prepared by Zhu Le,we will investigate the agent's cytotoxicity,antibacterial effects and observe its effect on experimental periodontitis through animal model and provide foundation for future clinical application.1. The cytotoxicity study of gallnut sustained-release gelAccording to Zhu Lei's methods, after gallnut sustained-release gel was mixed with magnetic blender for 1,3,5 days respectively, the 1d',3d'and 5d'gallnut sustained-release gel were prepared. Above-mentioned three gallnut sustained-release gel served as experimental groups, and Palio ointment was positive group (terminal concentration, 0.5g/ml phenol) and the negative control group was only culture medium. L-929 cell were cultured and treated by adding above different groups. Cell proliferation was detected by using MTT. The results showed: the 5d'gallnut sustained-release gel were similar with Palio ointment group and the negative control in density and morphology of culturing 1~ 7d L-929 cell. The cells present elongated spindle and polygonal, good spreading and arrayed with radial pattern. Cytotoxicity are gradeā
and accord with clinical requirements.2.The antibacterial experiment of gallnut sustained-release gel in vitroPg, Fn and Pi were cultured in vitro and detected by using disk diffusion method. The results showed that: gallnut sustained-release gel had some inhibitory effect on Pg,Fn and Pi and its inhibitory effect on Pg,Fn was better than Palio ointment. However, It had little effect on the Pi.3. The observation of treatment effect of gallnut sustained-release gel on experimental periodontitis in Beagle dogs7 of 2-year-old healthy Beagle dogs were selected, among which one was selected randomly as normal control without any treatment, and the other 6 were used as periodontal animal model. The maxillary second and third premolar and first molar and mandibular third premolar and the first and second molars were selected and ligated with surgical silk thread. After 30 days, an experimental dog and the normal control were killed and made histological samples. When experimental periodontitis model had been established according to the clinical standard of diagnosis and X-ray examination of periodontitis and histological observation, experimental teeth were divided into three group: group of gallnut sustained-release gel (experimental group); group of Palio ointment (positive control) and group of drug carrier lonely (blank control). Then treatment began by using each group of drugs once a week for lasting 4 weeks. GI, BOP, PD and other clinical parameters were examined after treatment of 1w, 2w, 3w and 4w respectively, and X-ray film were taken at the end of treatment. Tha results showed that experimental dog's periodontitis model had been established successfully after 30 days. After 4 weeks treatment, compared with baseline, PD, BOP, GI of the gallnut group and Palio ointment group had significantly improved(P <0.05), while blank control had no change, and as far as PD gallnut group was better than Palio group (P <0.05). X-ray examination showed that CEJ-B distance of gallnut group was shortened, while the Palio ointment group and blank group had no significant difference (P<0.05).4. The histological observation of gallnut sustained-release gel on experimental periodontitis of Beagle dogsExperimental process was the same with the previous experiment. After 4 weeks treatment, the animals were killed and the experimental teeth, periodontal tissue and the jaw samples were cut completely. The samples were prepared histological slices and stained by HE, then observed under microscopy. The distance between junctional epithelium and cemento-enamel junction (JE-CEJ) and new connective tissue (NCT) were measured. The new bone formation were observed with Meason trichrome staining and new bone height (NB) was measured with BI2000 image analysis software. The precision was 0.001mm. The results showed that: compared with the other two groups, sustained-gallnut release gel had the least JE-CEJ and NCT distance(P <0.05) and the most highest new bone height (NB)(P <0.05), while the Palio ointment had no significant difference in the JE-CEJ, NCT, NB compared with the control group (P> 0.05). |
PDF Full Text Request